My good colleague Nicco down in Italy says that constant bitrate podcasting is dead! Thats bold, but he does offer some interesting viewpoints on the advantages of VBR or variable bitrate recording.
“I think podcasters should avoid the MP3 Constant Bitrate. Putting a 64 or 96 CBR on a file containing speech as well as music is a waste of space� and the overall quality is poor. The best solution would be using Variable Bitrate (VBR) for the MP3 coding process. Like from 56 - 196 (just an example). This way the speech would be encoded in 56/64 kbits while encoding the music with higher bitrates (and quality).”
This could help out with the music portion of podcasts for sure, Nicco listens to Trend Radio and thinks the voice part is great at 64kpbs but thinks the music portions should be jacked up a bit. I guess its a matter of download time and bandwidth, clearly it would sound better. Maybe an experiment is in order!